I used this Telephoto Lens Back Pack for carrying my 400 2.8 lens attached to my camera and tele-extenders in the side pockets for photographing wildlife. It was a true lifesaver, protecting my heavy lens from rain and dust.
The two lower pockets are padded, the upper ones are not. The waist strap is adjustable and there is a chest strap also adjustable. There is also a peaked attachment to replace the top lid for an even longer lens. The case is nicely padded, as is the top of the lid.
The case measures 25" long with an outside diameter of 31". Replacing the flat lid with the peaked/domed lid adds about an extra 12".
There are 2 straps on the front for carrying a monopod.